Pump



F. E. BRADY, "JR 2,417,627

PUIP

March 18, 1947.

Filed Sept. 18, 1943 Shoots-Sheet 1 PatentedMar. 18,1941

umrizo STATES PATENT OFFICE This invention relates to pumps and moreparticularly to self-priming liquid pumps.

It is the principal object of the invention to provide a liquidpump ofthe rotary impeller type which has the capacity for rapid elf-priming assoon as it is placed in operation so that it will establish the flowwith a. minimum of delay, and which in operation is highly efficient andproduces desirable operating results.

It is a further object to provide such a pump in which residual liquidin the pump casing is delivered laterally into the path of travel of theimpeller blades from which the liquid is discharged at high velocitythrough the body of air trapped above the liquid, being discharged outwardly to effect rapid entrainment and discharge of the trapped air, toquickly prime the pump so that its normal suction will be rapidlyestablished and the pump thereafter continue to operate in an emcientand satisfactory manner.

Other objects and advantages will be apparent from the followingdescription, the accompanying drawing and the appended claims.

In the drawing,

Fig. 1 is a perspective view of a pump unit constructed in accordancewith the present invention and assembled with a drive motor;

Fig. 2 is an end elevational view of the pump housing removed from thesupporting motor. casing.

Fig. 3 is a vertical sectional view through the pump housing on the line3-3 of Fig. 4;

v Fig. 4 is a vertical sectional view through the pump housing on theline 4-4 of Fig. 2;

Fig. 5 is an elevational view of the impeller used in conjunction withthe invention;

Fig. 6 is a sectional view through the pump housing on the line 6-6 ofFig. 2; and

Fig. 7 is a broken sectional view on the line 1-1 of Fig. 2.

Pump construction have heretofore been pro-,

vided which embody features of self priming, that is, in which the pumpwill begin operation withnot provided a rapid self-priming action, orhave not accomplished such rapid action while at the same time providingfor satisfactory and eflicient operation of the pump in the normalpumping of the liquid. In cases where satisfactory pumping was obtained,the time required forthe priming of the pump under its own action wasexcessive and in other constructions where lesser 12 Claims. (01.103-113) 2 priming time was involved, this was accomplished by somesacrifice of efflciency during normal running.

In accordance with the present invention, not only is the normaloperation of the pump efflcient and highly satisfactory, but the timerequired for the pump to prime. itself is materially reducedsubstantially below that attained heretofore. In accordance with thepresent invention, the pump will be fully primed and in full operationwithin a very brief period after startin providing not only for theclearing of the air trapped in the pump chamber but also providing forthe discharge of such air as may be present in the suetionline. Thepriming is accomplished very rapidly, in most cases the full periodrequired being measured in terms of a few seconds with the time underfavorable conditions being of the order of one second or less. The pumptherefore is highly satisfactory not only for general pump applicationsin which it gives good results because of its high operating efficiency,but also in applications where the pump is repeatedly started andstopped by reason of the freedom from any ma-' teriai delay in thepriming of the pump.

Referring to the drawing, which discloses a perfected embodiment of theinvention, the assembled pump unit as shown in Fig. 1 comprises a drivemotor In suitably secured to a bracket II for mounting the pump on aconvenient support. To the forward end of the motor casing is secured anadapter casting l2, the pump housing 14 being bolted to the end face ofthe adapter by means of a pluralityof bolts IS.

The drive shaft of the motor extends through the adapter l2 and on theoverhanging end thereof receives the impeller shown at 20, the impellerbeing suitably fastened to the motor shaft by means of a set screw, 2|.The impeller is formed with a central hub portion 22 which projectsaxially beyond the blades which-are shown at 24, the blades having aninner curved part 23 and the outer part of the blades being of uniformwidth and the blades being inclined rearwardly in the direction ofrotation as indicated.

As shown and described herein the invention is shown as applied to apump in which the impeller rotates about a substantially horizontalaxis. The invention is so described for illustrative purposes, as it maybe similarly advantageously applied to a vertical axis pump, a pump ofsuch arrangement being ordinarily somewhat less difficult to prime thana horizontal axis pump.

The pump housing I4 is provided with a face 30 which is adapted to bereceived against the aemca'r 1 1 used to form a liquid tight sealproviding however for the ready separation and disassembly of the pumpwhen desired. Radially inwardly oi the face 30, the housing I4 is formedwith a central recess 32 which has communication with a downwardlyextending passage 33, such passage extending upwardly to a tappedopening 34 in the upper side of the case, to which a suitable supplypipe may be connected. This forms the suction side of the pump, thepassage 32 thus providing for the supply of the liquid through thesuction line and into the path of the impeller blades in a substantiallyaxially direction. It will also be noted that such supply of liquidtakes place to the inner part of the impeller where it is picked up bythe parts 23 of the impeller blades, being delivered thereby laterallyoutwardly toward the outer portions 24 of the blades.

The housing I4 is formed with a curved surface 36 defining a pumpcasing, so that such fluid as delivered to the blades will be forced totravel over the path as just described, the contour of the surface ofthe casing 36 closely conforming with that of the outer edges of theimpeller blades over the entire extent of those blades from the huboutwardly thereof;

Radially outwardly of the curved part 36 of the casing is a flat part 31which forms a continuation of the casing and in the assembled positionof the pump housing is spaced from the opposite plane face of theadapter I2 by a distance corresponding with the width oi. the outerparts 24 of the impeller blades with only enough clearance to give afree running fit, effectively sealing such blades within the pumpchamber so formed.

A volute passage 40 is formed outwardly of the casing 31, such passageextending below the level of surface 31 as indicated at 4|, to form aprogressive'y enlarged discharge space through which the liquid isdelivered being discharged outwardlyfrom the ends of the impellerblades. The wall of the casing is formed as shown at 43 to provide aseal for separating the inlet and discharge sides of the volute, thewall 43 extending inwardly to a position closely adjacent-the outerperiphery of the impeller blades to thereby eflec tive'y' seal the pumppassage.

The housing is formed to provide a sealing wall 40 which is located onthe upper part of the housing between the suction and dischargeconnections and in close radial relation with the outer peripheries ofthe impeller blades. A volute passage 42 extends from wall 43 around inthe direction of rotation of the blades with progressively increasingcross section. On the discharge side of the pump it has directcommunication with the main discharge outlet 45, the wall of the housingbeing formed with a lip 46 approximately at the level of .the horizontalaxis of the impeller beneath which the main discharge passage beginsextending upwardly into a cored discharge cham- 7 her 41. Above thischamber is the tapped outlet 48 which is adapted to receive a dischargepipe providing for the discharge of the pumped liquid.

Immediately adjacent the sealing wall 40 and on the discharge sidethereof there is provided an auxiliary discharge outlet 50, such outlethaving its upper end in communication with the discharge chamber 41providing for delivery thereto of discharged fluid, such fluid beingthus discharged through the same outlet as that flowing through the maindischarge outlet 45.

At its lower end auxiliary discharge outlet 50' has communication witha. passage 52 which is a 4 directly in line and in continuouscommunication with the volute passage 42. Passage 52 preterably extendsfrom the sealing wall 40 to the lip 46 and as shown may be defined by aconcentric wall of the housing l4 thus forming a-communieating passageof substantially uniform cross section throughout. It may have lessercross-sectional area than the adjacent part of the volute passagebecause it is not required to handle the entire volume of flow.

In order to provide for the rapid removal of air trapped within the pumpcasing, means are provided for assuring that liquid remaining within thepump casing will be delivered to the working surfaces of the blades, sothatwhen placed in operation, those blades will quickly deliver liquidinto and through the body of air above the liquid rather than merelycavitate through such liquid without establishing an eifective deliverythereof. Such liquid being discharged from the blades through the bodyof air serves to entrain the air and, placing it in motion, to direct itto the discharge chamber so that the pump chamher is rapidly scavengedand the pump thus freed of air and 'quickly enabled to begin its normaloperation.

For this purpose a passage is provided on the discharge side of the pumpchamber which affords communication between the liquid in the chamberand a point on the outer periphery of the impeller blades providing fora flow of liquid into the path ,of the blades in a substantially axialdirection. With such passage, and even under the very small or. almostnegligible pressure developed by the level of the liquid standing abovethe horizontal axis of the-pump, a definite flow will nevertheless takeplace directly into the path of the blades, that liquid being picked upon blade surfaces and quickly discharged in the manner and with theresults described above.

Such passage may be formed on either or both sides of the impeller.Preferably it is formed as a recess 55 in the 11% wall 31 of the casing.As shown it is located substantially at the level of the horizontal axisof the impeller on the discharge side thereof opposite the lower end ofthe main discharge passage 45 and with its lower end extendingdownwardly substantially to the horizontal axis. It may if desired belocated so as to extend below the horizontal axis.

As thus located recess .55 lies at least in part below the normal levelof the liquid within the pump casing, it being understood that at theend of any pump operation there is always a residual quantity of liquidleft within the pump. For initial operation, a separate priming opening58 is provided which is closed by a plug 59, the opening being incommunication with the suction inlet 33 to provide for filling the pumpchamber and thereby submerging part or all of recess '55.

When the pump is placed in operation with the liquid level above recess55, liquid is then supplied laterally of the blades in a generally axial.direction and directly into the path of travel 'is picked upanddelivered' along with the'liquld into' the discharge chamber 41.Theaction is analogous to the formation of an emulsion of liquid andair, the particles of liquid as they are broken up picking up the airand carrying the samealong with the liquid, the liquid howeverretaining-sufllcient mass so that its travel out- 6 charge passage withthe entrainment and discharge of the air in said pump casing.

3. In a self-priming rotary pump, the combination of a rotating impellerhaving a series of outwardly extending impeller blades, a pump casingproviding an inlet passage for supplying liquid centrally of saidimpeller blades, 9. main discharge outlet, an auxiliary discharge outleton a the discharge side of said-casing and located wardly throughtheoutlet ,5! and into chamber l'l' continues and the air is thusdischarged at tion takes place very rapidly, the flow. of liquid .15 thesame time. In actualoperation this condi-- quickly freeing the pum oftrapped air, and likewise providing for rapid removal of such air as maybe found in the suction line. It will also be clear that prior to theestablishment of the main flow out through the discharge passage 45, theliquid delivered to chamber 41 is free to how back through passage 45into the pump casing again where it is reused in themanner alreadydescribed, such action continuing until the air is flow established. Asstated, this occurs quite rapidly and the pump is rapidly primed and isthus brought into full operation with only a very brief period of delay,the delay in most cases being practically 'unnoticeable and in any eventunobjectionable.

While the form of apparatus herein described constitutes a preferredembodiment of the invention, it is tobe understood that the invention isnot limited to this precise form of apparatus, and that changes may bemade therein without departing from the scope of the invention which istending impeller blades having close running relation with the walls ofsaid pump chamber, said casing being formed to provide adischarge pas-.-sage in direct communication with said discharge chamber, an auxiliarydischarge passage in com.-

cleared from the pump chamber and the main Y said casing and locatedbeyond said main disbeyond said main discharge outlet in the directionof rotation, said casing being formed'flon the discharge side thereof inadvance of said auxiliary discharge passage with a laterally extendi grecess providing for the flow of liquid latera y into the path of saidimpeller blades to be dis charged thereby in finely divided formoutwardly through said auxiliary discharge passage to entrain and removeair within said casing.

4'. In a self-primingrotary pump, the combination of a rotating impellermounted for rotation about a substantially horizontal axis and having aseries of outwardly extending rearwardly inclined impeller blades, apump casing providing an inlet passage for supplying liquid in asubstantially axial direction to the central part of said impellerblades, a main discharge outlet, an auxiliary discharge outlet on thedischarge side of charge outlet in the direction 'of rotation, saidmunication with said discharge chamber, and

means on the discharge side of said pump chamber communicating with saiddischarge passage in advance thereof for supplying liquid laterally intothe path of the impeller blades to be dis- :charged thereby outwardlythrough said aux- 'a discharge outlet, an auxiliary discharge passage incommunication with said discharge chamber, and means communicatingdirectly with said discharge outlet and separated from said dis- 4charge chamber providing for supplying residual liquid within the pumpchamber laterally into the path of the impeller blades to be dischargedthereby outwardly through said auxiliary distrain and remove air withinsaid casing.

5. In a' self-priming liquid pump of the character described, thecombination of a rotary impeller having plurality of impeller blades, a.pump casing having an inlet passage for supplying fluid to said impellersubstantially centrally thereof, said pump casing forming a volutepassage located radially outwardly of said impeller, a main dischargeoutlet communicating with said volute passage on the discharge sidethereof, means for sealing the discharge side of said passage from theinlet side thereof, an auxiliary discharge outlet, and means located inadvance of said auxiliary outlet and opening into said volute passageproviding for the flow of liquid laterally into the path of travel'ofsaid blades to supply liquid to said blades to be discharged therebyinto the air above the liquid in said pump casing to cause entrainmentof said air and discharge thereof with said liquid through saidauxiliary discharge outlet.

6. In a self-priming liquid pump of the char acter described, thecombination of a rotary impeller having plurality of impeller blades, a,pump casing having an inlet passage for supplying fluid to said impellersubstantially, centrally thereof,

said pump casing forming a volute passage located radially outwardly ofsaid impeller, a main discharge outlet, communicating with said voluteand means located in advance of said auxiliary outlet and openinginto-the radially inner side of said volute passage providing for theflow of liquid laterally into the path of travel of said blades tosupply liquid to said blades to be discharged thereby into the air airand discharge thereof with said liquid through said auxiliary dischargeoutlet.

side of said volute passage beyond the point of communication therewithof said main discharge outlet, and means forming a recess in the wall ofsaid casing in advance of said auxiliary discharge outlet andsubstantially at the point of communication of said passage and saidmain discharge outlet providing for the lateral how of liquid into thepath of travel of said impeller blades to discharge a mass of liquid infinelydivided form through said auxiliary discharge outlet withaccompanying entrainment and discharge of the air within said casing.

8. In a self-priming liquid pump of the type described, the combinationof a rotary impeller having a plurality of impeller blades, a pumpcasing having an inlet for supplying liquid to said impellersubstantially centrally thereof, said casing being formed to define avolute passage located radially outwardly of said impeller, means forsealing the inlet side of said passage from the discharge side thereof,a main discharge outlet in communication with said volute passage on thedischarge side thereof, means defining a lip on said casing for closingthe wall of said main discharge passage, an auxiliary discharge outletadjacent said sealing means, said casing being formed to define acommunicating passage extending from said lip to the opening of-saidauxiliary discharge outlet, the side wall of said pump casinglbeingrecessedproviding for supplyof liquid laterally into the path of travelof said impeller blades to discharge a substantial,

mass of liquid through said communicating passage and into saidauxiliary discharge outlet to entrain and remove the air from said pumpcasing. 1

9. In a. self-priming liquid pump of the type described, the combinationof a,rotary impeller having a plurality of impeller blades, a pumpcasing having an inlet for supplying liquid to said impellersubstantially centrally thereof, said casing being formed to define avolute passage located radially outwardly of said impeller, means forsealing the inlet side of said passage from the discharge side thereof,a main discharge outlet in communication with said volute passage on thedischarge side thereof, means defining a lip on said casing forclosingthe wall. of said main discharge passage, an auxiliary dischargeoutlet adjacent said sealing means said casing being formed to define acommunicating passage extending from said lip to the opening of saidauxiliary discharge outlet, the side wall of said pump casing beingrecessed substantially in the zone of said lip providing for supply ofliquid laterally into the path of travel of said impeller blades todischarge a substantial mass of liquid through said communicatingpassage and into I above the liquid in said pump casing to causeentrainment of said said auxiliary discharge outlet to entrain and Iremove the air from said pump casing. 10. In a'self-priming liquid pumpof the char acter described, the combination of a rotary impeller havinga plurality of impeller blades, a pump casing having an inlet passagefor supply fluid to said impeller substantially axially thereof, meansdefining a volute passage located radially outwardly of said impeller,means adjacent the lateral flow of liquid into the path of said im-'peller blades to be discharged thereby toward and through said auxiliarydischarge outlet with accompanying entrainment of air above said liquidlevel to provide rapid priming of said pump.

11. In a self-priming liquid pump of the character described, thecombination of a rotary impeller having a plurality of impeller bladesadapted for rotation about a substantially hori-- zontal axis andrearwardly inclined in a direction of rotation, a pump casing having aninlet passage for supplying fluid to said impeller substantially axiallythereof, means defining a volute passage located radially outwardly ofsaid impeller, means for sealing the inlet from the discharge side ofsaid passage, a main discharge outlet communicating with said volutepassage on the discharge side of said impeller approximately at thehorizontal axis thereof, an auxiliary discharge outlet alsocommunicating with said passage above the point of communication of saidmain discharge outlet and substantially adjacent said sealing means, thelateral wall of said pump casing at approximately the level of thehorizontal axis thereof and below the normal liquid level within saidcasing being recessed away from said impeller to provide for lateralflow of liquid into the path of said impeller blades to be dischargedthereby toward and through said auxiliary discharge outlet withaccompanying entrainment of air above said,

7 pump.

12. In a self-priming pump of the character described, the combinationof a rotary impeller having a plurality of impeller blades adapted forrotation about a substantially horizontal axis, a pump casing'havlng aninlet passage for supplying fluid to said impeller substantially axiallythereof, means defining a volute passage located radially outwardly ofsaid impeller, means for sealing the inlet from the discharge side ofsaid passage, a main discharge outlet communicating with said volutepassage on the discharge side of said impeller approximately atthehorizontal axis thereof, an auxiliary discharge outlet alsocommunicating with said passage, the lateral wall of said pump casing atapproximately the level of the horizontal axis thereof and below thenormal liquid level within said casing being recessed away from saidimpeller to provide for lateral flow of liquid into the path of saidimpeller blades to be discharged thereby toward and through saidauxiliary discharge outlet with accompanying entrainment of I air abovesaid liquid level to provide rapid prim- Number ing 01 said pump.2,224,615 FRANCIS E. BRADY, JR. 2,181,792 2,019,143

REFERENCES CITED 2,005,466 The following references are of record in the2163'951 file of this patent:

UNITED STATES m'mm's Number Name Date 10 Number LaBour Mar. 23, 1926Name Date Stratton Dec. 10,1940 Rupp et a1 Nov. 28, 1939 LaBour Oct. 29,1935 LaBour June 18, 1935 LaBour June 2'7, 1939 FOREIGN PATENTS CountryDate British .Sept. 22, 1937

